2 * Copyright (c) 1991, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 #if defined(AUTHENTICATION) && defined(ENCRYPTION) && defined(DES_ENCRYPTION)
39 #include <arpa/telnet.h>
51 #include "misc-proto.h"
53 #include "crypto-headers.h"
55 extern int encrypt_debug_mode;
63 #define IN_PROGRESS (NO_SEND_IV|NO_RECV_IV|NO_KEYID)
69 DES_cblock str_output;
73 DES_key_schedule str_sched;
79 DES_cblock krbdes_key;
80 DES_key_schedule krbdes_sched;
82 unsigned char fb_feed[64];
86 struct stinfo streams[2];
89 static struct fb fb[2];
98 { "\0", 1, 0, 0, 0 }, /* default key of zero */
102 #define KEYFLAG_MASK 03
104 #define KEYFLAG_NOINIT 00
105 #define KEYFLAG_INIT 01
106 #define KEYFLAG_OK 02
107 #define KEYFLAG_BAD 03
109 #define KEYFLAG_SHIFT 2
111 #define SHIFT_VAL(a,b) (KEYFLAG_SHIFT*((a)+((b)*2)))
115 #define FB64_IV_BAD 3
118 void fb64_stream_iv (DES_cblock, struct stinfo *);
119 void fb64_init (struct fb *);
120 static int fb64_start (struct fb *, int, int);
121 int fb64_is (unsigned char *, int, struct fb *);
122 int fb64_reply (unsigned char *, int, struct fb *);
123 static void fb64_session (Session_Key *, int, struct fb *);
124 void fb64_stream_key (DES_cblock, struct stinfo *);
125 int fb64_keyid (int, unsigned char *, int *, struct fb *);
126 void fb64_printsub(unsigned char *, size_t ,
127 unsigned char *, size_t , char *);
129 void cfb64_init(int server)
132 fb[CFB].fb_feed[4] = ENCTYPE_DES_CFB64;
133 fb[CFB].streams[0].str_flagshift = SHIFT_VAL(0, CFB);
134 fb[CFB].streams[1].str_flagshift = SHIFT_VAL(1, CFB);
138 void ofb64_init(int server)
141 fb[OFB].fb_feed[4] = ENCTYPE_DES_OFB64;
142 fb[CFB].streams[0].str_flagshift = SHIFT_VAL(0, OFB);
143 fb[CFB].streams[1].str_flagshift = SHIFT_VAL(1, OFB);
146 void fb64_init(struct fb *fbp)
148 memset(fbp,0, sizeof(*fbp));
149 fbp->state[0] = fbp->state[1] = FAILED;
150 fbp->fb_feed[0] = IAC;
151 fbp->fb_feed[1] = SB;
152 fbp->fb_feed[2] = TELOPT_ENCRYPT;
153 fbp->fb_feed[3] = ENCRYPT_IS;
158 * -1: some error. Negotiation is done, encryption not ready.
159 * 0: Successful, initial negotiation all done.
160 * 1: successful, negotiation not done yet.
161 * 2: Not yet. Other things (like getting the key from
162 * Kerberos) have to happen before we can continue.
164 int cfb64_start(int dir, int server)
166 return(fb64_start(&fb[CFB], dir, server));
169 int ofb64_start(int dir, int server)
171 return(fb64_start(&fb[OFB], dir, server));
174 static int fb64_start(struct fb *fbp, int dir, int server)
183 * This is simply a request to have the other side
184 * start output (our input). He will negotiate an
185 * IV so we need not look for it.
187 state = fbp->state[dir-1];
193 state = fbp->state[dir-1];
196 else if ((state & NO_SEND_IV) == 0) {
200 if (!VALIDKEY(fbp->krbdes_key)) {
205 state &= ~NO_SEND_IV;
207 if (encrypt_debug_mode)
208 printf("Creating new feed\r\n");
210 * Create a random feed and send it over.
213 if (RAND_bytes(fbp->temp_feed,
214 sizeof(*fbp->temp_feed)) != 1)
216 DES_set_odd_parity(&fbp->temp_feed);
217 } while(DES_is_weak_key(&fbp->temp_feed));
219 p = fbp->fb_feed + 3;
223 for (x = 0; x < sizeof(DES_cblock); ++x) {
224 if ((*p++ = fbp->temp_feed[x]) == IAC)
229 printsub('>', &fbp->fb_feed[2], p - &fbp->fb_feed[2]);
230 telnet_net_write(fbp->fb_feed, p - fbp->fb_feed);
235 return(fbp->state[dir-1] = state);
240 * -1: some error. Negotiation is done, encryption not ready.
241 * 0: Successful, initial negotiation all done.
242 * 1: successful, negotiation not done yet.
245 int cfb64_is(unsigned char *data, int cnt)
247 return(fb64_is(data, cnt, &fb[CFB]));
250 int ofb64_is(unsigned char *data, int cnt)
252 return(fb64_is(data, cnt, &fb[OFB]));
256 int fb64_is(unsigned char *data, int cnt, struct fb *fbp)
259 int state = fbp->state[DIR_DECRYPT-1];
266 if (cnt != sizeof(DES_cblock)) {
267 if (encrypt_debug_mode)
268 printf("CFB64: initial vector failed on size\r\n");
273 if (encrypt_debug_mode)
274 printf("CFB64: initial vector received\r\n");
276 if (encrypt_debug_mode)
277 printf("Initializing Decrypt stream\r\n");
279 fb64_stream_iv(data, &fbp->streams[DIR_DECRYPT-1]);
281 p = fbp->fb_feed + 3;
282 *p++ = ENCRYPT_REPLY;
287 printsub('>', &fbp->fb_feed[2], p - &fbp->fb_feed[2]);
288 telnet_net_write(fbp->fb_feed, p - fbp->fb_feed);
290 state = fbp->state[DIR_DECRYPT-1] = IN_PROGRESS;
294 if (encrypt_debug_mode) {
295 printf("Unknown option type: %d\r\n", *(data-1));
302 * We failed. Send an FB64_IV_BAD option
303 * to the other side so it will know that
306 p = fbp->fb_feed + 3;
307 *p++ = ENCRYPT_REPLY;
312 printsub('>', &fbp->fb_feed[2], p - &fbp->fb_feed[2]);
313 telnet_net_write(fbp->fb_feed, p - fbp->fb_feed);
317 return(fbp->state[DIR_DECRYPT-1] = state);
322 * -1: some error. Negotiation is done, encryption not ready.
323 * 0: Successful, initial negotiation all done.
324 * 1: successful, negotiation not done yet.
327 int cfb64_reply(unsigned char *data, int cnt)
329 return(fb64_reply(data, cnt, &fb[CFB]));
332 int ofb64_reply(unsigned char *data, int cnt)
334 return(fb64_reply(data, cnt, &fb[OFB]));
338 int fb64_reply(unsigned char *data, int cnt, struct fb *fbp)
340 int state = fbp->state[DIR_ENCRYPT-1];
347 fb64_stream_iv(fbp->temp_feed, &fbp->streams[DIR_ENCRYPT-1]);
350 state &= ~NO_RECV_IV;
351 encrypt_send_keyid(DIR_ENCRYPT, (unsigned char *)"\0", 1, 1);
355 memset(fbp->temp_feed, 0, sizeof(DES_cblock));
356 fb64_stream_iv(fbp->temp_feed, &fbp->streams[DIR_ENCRYPT-1]);
361 if (encrypt_debug_mode) {
362 printf("Unknown option type: %d\r\n", data[-1]);
371 return(fbp->state[DIR_ENCRYPT-1] = state);
374 void cfb64_session(Session_Key *key, int server)
376 fb64_session(key, server, &fb[CFB]);
379 void ofb64_session(Session_Key *key, int server)
381 fb64_session(key, server, &fb[OFB]);
384 static void fb64_session(Session_Key *key, int server, struct fb *fbp)
387 if (!key || key->type != SK_DES) {
388 if (encrypt_debug_mode)
389 printf("Can't set krbdes's session key (%d != %d)\r\n",
390 key ? key->type : -1, SK_DES);
393 memcpy(fbp->krbdes_key, key->data, sizeof(DES_cblock));
395 fb64_stream_key(fbp->krbdes_key, &fbp->streams[DIR_ENCRYPT-1]);
396 fb64_stream_key(fbp->krbdes_key, &fbp->streams[DIR_DECRYPT-1]);
398 RAND_seed(key->data, key->length);
400 DES_set_key_checked((DES_cblock *)&fbp->krbdes_key,
403 * Now look to see if krbdes_start() was waiting for the key to
404 * show up. If so, go ahead an call it now that we have the key.
406 if (fbp->need_start) {
408 fb64_start(fbp, DIR_ENCRYPT, server);
413 * We only accept a keyid of 0. If we get a keyid of
414 * 0, then mark the state as SUCCESS.
417 int cfb64_keyid(int dir, unsigned char *kp, int *lenp)
419 return(fb64_keyid(dir, kp, lenp, &fb[CFB]));
422 int ofb64_keyid(int dir, unsigned char *kp, int *lenp)
424 return(fb64_keyid(dir, kp, lenp, &fb[OFB]));
427 int fb64_keyid(int dir, unsigned char *kp, int *lenp, struct fb *fbp)
429 int state = fbp->state[dir-1];
431 if (*lenp != 1 || (*kp != '\0')) {
441 return(fbp->state[dir-1] = state);
444 void fb64_printsub(unsigned char *data, size_t cnt,
445 unsigned char *buf, size_t buflen, char *type)
451 buf[buflen-1] = '\0'; /* make sure it's NULL terminated */
456 snprintf(lbuf, sizeof(lbuf), "%s_IV", type);
461 snprintf(lbuf, sizeof(lbuf), "%s_IV_OK", type);
466 snprintf(lbuf, sizeof(lbuf), "%s_IV_BAD", type);
471 snprintf(lbuf, sizeof(lbuf), " %d (unknown)", data[2]);
474 for (; (buflen > 0) && (*buf = *cp++); buf++)
476 for (i = 3; i < cnt; i++) {
477 snprintf(lbuf, sizeof(lbuf), " %d", data[i]);
478 for (cp = lbuf; (buflen > 0) && (*buf = *cp++); buf++)
485 void cfb64_printsub(unsigned char *data, size_t cnt,
486 unsigned char *buf, size_t buflen)
488 fb64_printsub(data, cnt, buf, buflen, "CFB64");
491 void ofb64_printsub(unsigned char *data, size_t cnt,
492 unsigned char *buf, size_t buflen)
494 fb64_printsub(data, cnt, buf, buflen, "OFB64");
497 void fb64_stream_iv(DES_cblock seed, struct stinfo *stp)
500 memcpy(stp->str_iv, seed,sizeof(DES_cblock));
501 memcpy(stp->str_output, seed, sizeof(DES_cblock));
503 DES_set_key_checked(&stp->str_ikey, &stp->str_sched);
505 stp->str_index = sizeof(DES_cblock);
508 void fb64_stream_key(DES_cblock key, struct stinfo *stp)
510 memcpy(stp->str_ikey, key, sizeof(DES_cblock));
511 DES_set_key_checked((DES_cblock*)key, &stp->str_sched);
513 memcpy(stp->str_output, stp->str_iv, sizeof(DES_cblock));
515 stp->str_index = sizeof(DES_cblock);
519 * DES 64 bit Cipher Feedback
525 * INPUT --(--------->(+)+---> DATA
531 * iV: Initial vector, 64 bits (8 bytes) long.
532 * Dn: the nth chunk of 64 bits (8 bytes) of data to encrypt (decrypt).
533 * On: the nth chunk of 64 bits (8 bytes) of encrypted (decrypted) output.
537 * V(n+1) = DES(On, key)
540 void cfb64_encrypt(unsigned char *s, int c)
542 struct stinfo *stp = &fb[CFB].streams[DIR_ENCRYPT-1];
545 index = stp->str_index;
547 if (index == sizeof(DES_cblock)) {
549 DES_ecb_encrypt(&stp->str_output, &b,&stp->str_sched, 1);
550 memcpy(stp->str_feed, b, sizeof(DES_cblock));
554 /* On encryption, we store (feed ^ data) which is cypher */
555 *s = stp->str_output[index] = (stp->str_feed[index] ^ *s);
559 stp->str_index = index;
562 int cfb64_decrypt(int data)
564 struct stinfo *stp = &fb[CFB].streams[DIR_DECRYPT-1];
569 * Back up one byte. It is assumed that we will
570 * never back up more than one byte. If we do, this
571 * may or may not work.
578 index = stp->str_index++;
579 if (index == sizeof(DES_cblock)) {
581 DES_ecb_encrypt(&stp->str_output,&b, &stp->str_sched, 1);
582 memcpy(stp->str_feed, b, sizeof(DES_cblock));
583 stp->str_index = 1; /* Next time will be 1 */
584 index = 0; /* But now use 0 */
587 /* On decryption we store (data) which is cypher. */
588 stp->str_output[index] = data;
589 return(data ^ stp->str_feed[index]);
593 * DES 64 bit Output Feedback
600 * INPUT -------->(+) ----> DATA
603 * iV: Initial vector, 64 bits (8 bytes) long.
604 * Dn: the nth chunk of 64 bits (8 bytes) of data to encrypt (decrypt).
605 * On: the nth chunk of 64 bits (8 bytes) of encrypted (decrypted) output.
608 * V(n+1) = DES(Vn, key)
612 void ofb64_encrypt(unsigned char *s, int c)
614 struct stinfo *stp = &fb[OFB].streams[DIR_ENCRYPT-1];
617 index = stp->str_index;
619 if (index == sizeof(DES_cblock)) {
621 DES_ecb_encrypt(&stp->str_feed,&b, &stp->str_sched, 1);
622 memcpy(stp->str_feed, b, sizeof(DES_cblock));
625 *s++ ^= stp->str_feed[index];
628 stp->str_index = index;
631 int ofb64_decrypt(int data)
633 struct stinfo *stp = &fb[OFB].streams[DIR_DECRYPT-1];
638 * Back up one byte. It is assumed that we will
639 * never back up more than one byte. If we do, this
640 * may or may not work.
647 index = stp->str_index++;
648 if (index == sizeof(DES_cblock)) {
650 DES_ecb_encrypt(&stp->str_feed,&b,&stp->str_sched, 1);
651 memcpy(stp->str_feed, b, sizeof(DES_cblock));
652 stp->str_index = 1; /* Next time will be 1 */
653 index = 0; /* But now use 0 */
656 return(data ^ stp->str_feed[index]);